How does the OleDbDataAdapter Update work?

[dav...@hotmail.com]

I know this is really basic but I am baffled trying to get the
DataAdapter Update to work.

Let's say I simply want to change all names "Smith" to "Jones" and I
want to use the DataAdapter and DataTable to do it.

So I try this:

// assume the OleDbConnection conn is already open
OleDbCommand cmd = new OleDbCommand("select lastname from employee",
conn);
OleDbDataAdapter data = new OleDbDataAdapter(cmd);

DataSet ds = new DataSet();
data.Fill(ds, "mydata");

DataTable dt = ds.Tables[0];
DataRow[] rows = dt.Select();

for (int i = 0; i < rows.Length; i++)
{
DataRow row = rows[i];
string curVal = row["lastname"].ToString();
if (curVal == "Smith")
{
row["lastname"] = "Jones";
rows[i] = row;
}
}
data.Update(rows);

This doesn't work because it "requires a valid UpdateCommand"...
But I don't follow this at all. Sure, I could explicitly write an
update command like so...

OleDbCommand command = new OleDbCommand("UPDATE employee SET lastname
= 'Jones' WHERE lastname = 'Smith'", conn);
data.UpdateCommand = command;

...but then what's the point of allowing me to edit the DataRow and
having an Update() command in the first place?
I know I can do this simply and more efficiently with the
connection's ExecuteNonQuery, but for reasons that I can go into if
necessary I really need an approach like this where I iterate through
each record and programmatically review it before updating it.

Thanks
Dave

[Bob Barrows]

dav...@hotmail.com wrote:
> I know this is really basic but I am baffled trying to get the
> DataAdapter Update to work.
>

There was no way for you to know it (except maybe by browsing through
some of the previous questions in this newsgroup before posting yours -
always a recommended practice) , but this (microsoft.public.data.ado) is
a classic (COM-based) ADO newsgroup. ADO.Net bears very little
resemblance to classic ADO so, while you may be lucky enough to find a
dotnet-knowledgeable person here who can answer your question, you can
eliminate the luck factor by posting your question to a group where
those dotnet-knowledgeable people hang out. I suggest
microsoft.public.dotnet.framework.adonet.

--
HTH,
Bob Barrows